Problem: A permutation p is an ordered group of numbers p1, p2, ..., pn, consisting of n distinct positive integers, each is no more than n. We'll define number n as the length of permutation p1, p2, ..., pn.

Simon has a positive integer n and a non-negative integer k, such that 2k ≤ n. Help him find permutation a of length 2n, such that it meets this equation: <image>.

Input

The first line contains two integers n and k (1 ≤ n ≤ 50000, 0 ≤ 2k ≤ n).

Output

Print 2n integers a1, a2, ..., a2n — the required permutation a. It is guaranteed that the solution exists. If there are multiple solutions, you can print any of them.

Examples

Input

1 0


Output

1 2

Input

2 1


Output

3 2 1 4


Input

4 0


Output

2 7 4 6 1 3 5 8

Note

Record |x| represents the absolute value of number x. 

In the first sample |1 - 2| - |1 - 2| = 0.

In the second sample |3 - 2| + |1 - 4| - |3 - 2 + 1 - 4| = 1 + 3 - 2 = 2.

In the third sample |2 - 7| + |4 - 6| + |1 - 3| + |5 - 8| - |2 - 7 + 4 - 6 + 1 - 3 + 5 - 8| = 12 - 12 = 0.

Solution (in JAVA):

Solution:
/*
 ~/BAU/ACM-ICPC/Teams/Rampage/MMZA
 ~/sudo apt-get verdict Accepted
 practice...
*/
//package javaapplication1;

//import java.util.Scanner;


import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.math.BigDecimal;
import java.util.*;

public class Main {
    static final int Mod=(int)1e9+7;
    static final int N=303;
    
    public static void main(String[] args) throws IOException {
       // Reader.init(System.in);
        //Scanner in=new Scanner(new FileInputStream("input.txt"));
        FastReader in=new FastReader();
        //in=new FileReader("input.txt");
        //PrintWriter out=new PrintWriter(new FileOutputStream("output.txt"));
        PrintWriter out=new PrintWriter(System.out);           
        Main ob=new Main();
        int n=in.nextInt(),k=in.nextInt();
        
        for(int i=1;i<=n;i++){
            if(i>1)
                out.print(" ");
            if(i<=k){
                out.print((2*i)+" "+(2*i-1));
            }
            else 
                out.print((2*i-1)+" "+(2*i));
        }
        out.println("");
        out.close();
    }
    String sort(String inputString) 
    { 
        ArrayList<Character> arr=new ArrayList();
        for(int i=0;i<inputString.length();i++)
            arr.add(inputString.charAt(i));
        Collections.sort(arr);
        StringBuilder sb=new StringBuilder();
        for(int i=0;i<arr.size();i++)
            sb.append(arr.get(i));
        
        return sb.toString(); 
    } 
     
    boolean next_permutation(int[] p, int len) {
        int a = len - 2;
        while (a >= 0 && p[a] >= p[a + 1]) {
            a--;
        }

        if (a == -1) {
            return false;
        }

        int b = len - 1;
        while (p[b] <= p[a]) {
            b--;
        }

        p[a] += p[b];
        p[b] = p[a] - p[b];
        p[a] -= p[b];

        for (int i = a + 1, j = len - 1; i < j; i++, j--) {
            p[i] += p[j];
            p[j] = p[i] - p[j];
            p[i] -= p[j];
        }

        return true;
    }
    int lower_bound(ArrayList<Integer> arr,int key) {
        int len = arr.size();
        int lo = 0;
        int hi = len-1;
        int mid = (lo + hi)/2;
        while (true) {
            int cmp = (arr.get(mid)==key?1:0);
            if (cmp == 0 || cmp > 0) {
                hi = mid-1;
                if (hi < lo)
                    return mid;
            } else {
                lo = mid+1;
                if (hi < lo)
                    return mid<len-1?mid+1:-1;
            }
            mid = (lo + hi)/2;
        }
    }
    int upper_bound(ArrayList<Integer> arr, int key) {
        int len = arr.size();
        int lo = 0;
        int hi = len-1;
        int mid = (lo + hi)/2;
        while (true) {
            int cmp = (arr.get(mid)==key?1:0);
            if (cmp == 0 || cmp < 0) {
                lo = mid+1;
                if (hi < lo)
                    return mid<len-1?mid+1:-1;
            } else {
                hi = mid-1;
                if (hi < lo)
                    return mid;
            }
            mid = (lo + hi)/2;
        }
    }
    int gcd(int a,int b){
        return b==0?a:gcd(b,a%b);
    } 
    double area(ArrayList<Point> arr){
        double sum=0.0;
        for(int i=0;i<arr.size();i++){
            sum+=cross(arr.get(i),arr.get(((i+1)%(int)arr.size())));
        }
        return Math.abs(sum)/2.0;
    }
    double dot(Point p,Point q){
        return (p.x*q.x+p.y*q.y);
    }
    double cross(Point p,Point q){
        return (p.x*q.y-p.y*q.x);
    }
    Point computeLineIntersection(Point a,Point b,Point c,Point d){
        b=b.sub(a);d=c.sub(d);c=c.sub(a);
        return a.add(b.mulCon(cross(c,d)).devideCon(cross(b,d)));
    }
   static class FastReader 
        { 
        BufferedReader br; 
        StringTokenizer st; 
  
        public FastReader() 
        { 
            br = new BufferedReader(new
                     InputStreamReader(System.in)); 
        } 
  
        String next() 
        { 
            while (st == null || !st.hasMoreElements()) 
            { 
                try
                { 
                    st = new StringTokenizer(br.readLine()); 
                } 
                catch (IOException  e) 
                { 
                    e.printStackTrace(); 
                } 
            } 
            return st.nextToken(); 
        } 
  
        int nextInt() 
        { 
            return Integer.parseInt(next()); 
        } 
  
        long nextLong() 
        { 
            return Long.parseLong(next()); 
        } 
  
        double nextDouble() 
        { 
            return Double.parseDouble(next()); 
        } 
  
        String nextLine() 
        { 
            String str = ""; 
            try
            { 
                str = br.readLine(); 
            } 
            catch (IOException e) 
            { 
                e.printStackTrace(); 
            } 
            return str; 
        } 
    } 
  
}
class Reader {

    static BufferedReader reader;
    static StringTokenizer tokenizer;

    static void init(InputStream input) throws UnsupportedEncodingException {
        reader = new BufferedReader(
                new InputStreamReader(input, "UTF-8"));
        tokenizer = new StringTokenizer("");
    }

    static void init(String url) throws FileNotFoundException {
        reader = new BufferedReader(new FileReader(url));
        tokenizer = new StringTokenizer("");
    }

    static String next() throws IOException {
        while (!tokenizer.hasMoreTokens()) {
            //TODO add check for eof if necessary
            tokenizer = new StringTokenizer(
                    reader.readLine());
        }
        return tokenizer.nextToken();
    }

    static String nextLine() throws IOException {
        return reader.readLine();
    }

    static int nextInt() throws IOException {
        return Integer.parseInt(next());
    }

    static double nextDouble() throws IOException {
        return Double.parseDouble(next());
    }

    static long nextLong() throws IOException {
        return Long.parseLong(next());
    }
}
class Point{    
    double x,y;
    Point(double _x,double _y){
        x=_x;
        y=_y;
    }
    Point add(final Point p){
        return new Point(x+p.x,y+p.y);
    }
    Point sub(final Point p){
        return new Point(x-p.x,y-p.y);
    }
    Point mulCon(final double c){
        return new Point(c*x,c*y);
    }
    Point devideCon(final double c){
        return new Point(x/c,y/c);
    }
}
class  pair implements Comparator<pair>{
    int x,y;
    pair(){}
    pair(int a,int b){
        x=a;
        y=b;
    }
    @Override 
    public int compare(pair a,pair b){
        return a.x-b.x;
    }
}